In recent years, a lot types of external devices are widely used to assist display and projection. For example, when a computer is used for presentation, the screen must be mirrored to the projector, so that content displayed on the computer screen is instantly projected onto the projection screen. Conventionally, a D-sub, a DVI or an HDMI wire is used to connect the computer and the projector for implementing the projection. However, the method herein is limited to the wired connection.
To avoid the limitation, the image transmission device is developed to implement the wireless connection between the computer and the screen/projector. In general, an image transmission device of this type usually comprises an image storage unit for storing relevant software programs and/or drivers; when the image transmission device is connected to a computer of a user, the computer will recognize the image transmission device as a universal serial bus (USB) mass storage device for providing the user to duplicate, install or execute the software on this image transmission device.
However, there are at least two drawbacks. Firstly, based on the reasons of data safety, more and more organizations (such as general companies, banks, government agencies, etc.) disable the functionality of the USB mass storage device in the staff computers. Under this circumstance, the image transmission devices described above become useless. Secondly, since the drivers or software on the image transmission device have to be installed and updated, the USB disk of the image transmission device must be writable. Because the software viruses or malwares are possible to be written to the image transmission device, the safety risks are occurred.
Therefore, there is a need of providing an improved image transmission device, an image transmission method, and an image transmission system, which are distinct from the prior art in order to solve the above drawbacks.